How to Test an Expert Advisor (EA) on an MT5 Demo Account

Why demo first is non-negotiable

However good the backtest, it's still history. A demo account runs on live prices with virtual money, verifying three things a backtest never can: the EA's real behavior on your broker's feed, the actual impact of spread and slippage, and your own psychology while watching a floating loss.

Two minutes to open

1. In MT5, go to File → Open an Account (demo).
2. Pick a server (your broker's demo server is fine) and fill in basic details.
3. Set the virtual balance (tip: use the amount you actually plan to trade live — the experience stays honest) and leverage.
4. MT5 logs in automatically; "Demo" appears in the bottom corner.

What to watch during the demo period

• Do trade frequency and holding time roughly match the backtest?
• Are stops and targets executed exactly by the rules?
• When a losing streak comes, are you still willing to let it run? (This one matters most.)

Give it at least 2–4 weeks before deciding anything. Impatience is the most expensive habit in trading.